US2167531A - Treatment of hydrocarbon oils - Google Patents

Description

INVENTOl-' JEAN DELATTRE sEGUY July 25, 1939 J. D. sEGUY TREATMENT 0F HYDROGARBON OILS Original Filed July 28, 1930 Patented July 25, 1939 UNITED STATES PATENT OFFICE TREATBIENT OF HYDROCARBON OILS Walle VApplication July 28, 1930, Serial No. 471,206 Renewed May 4, 1938 5 Claims.

This invention contemplates an improved process for the treatment of hydrocarbon oils, particularly for the conversion of so-called heavy or high boiling hydrocarbon oils into lower boiling hydrocarbon oils.

The invention provides a process in which hydrocarbon oils are subjected to cracking conditions and the vapors and unvaporized liquid are separately treated.

In one specific aspect the process comprises subjecting the oil to a liquid-vapor phase cracking treatment under heat and pressure, discharging the hydrocarbon material at conversion temperature into a vaporizing zone at substantially lower pressure, separating the vaporized and unvaporized products therein, subjecting the vapors to a dephlegmating or iractionating action, segregating during the process heavier and lighter reflux condensates, separately returning said heavier and lighter condensates to separate heating elements where they are treated under vapor phase conditions, separating the lower boiling components of the vapors from the fractionating zone, and cooling, condensing and collecting the lower boiling distillate product of the process.

My process also provides an operation wherein the oil being treated may be reduced to coke and distillate containing the low boiling products of the process.

My invention further provides a process for the production of high anti-knock gasoline.

The invention will be more fully described by reference to the accompanying diagrammatic drawing, which is not to scale, and which illustrates one form of apparatus suitable for carrying out the process of the invention.

The raw oil charging stock for the process may be fed through line I, valve 2, pump 3, valve 4, line 5 and heat exchanger 6 which permits indirect heat exchange between the incoming raw oil and the vapors in the fractionating zone, causing a partial condensation of said vapors, the resulting reilux condensate being returned as hereinafter described. The oil leaving the indirect heat exchanger 6 passes through line l, valve 8, line 9, and valve I into heating element I I located in any suitable furnace setting I2. A portion or all of the raw oil may be passed directly through line I3 controlled by valve I4 into line 9 and through the heating element II. The oil after being raised to conversion temperature passes through the transfer line I5 controlled by valve I6 into the ilashing and vaporizing zone I'I which is under a substantially reduced pressure with respect to the heating element I I.

The unvaporized liquid residue when formed is withdrawn through line I8 controlled by valve I9. The vapors resulting from the flashing operation pass through riser into compartment 2| of the fractionating column 22. The reflux condensate which collects upon the deck or plate 23 in the fractionating column 22 may be withdrawn through line 24 controlled by valve 25 and pumped by means of pump 26 through line 21 and valve 28 into the vapor phase heating element 29 located in any suitable furnace setting 30. The highly heated vapors are discharged through line 3l and valve 32 back into the flashing and vaporizing zone II. Similarly, the vapors leaving compartment 2l pass through riser 33 into compartment 34 of the fractionating column 22 and the reflux condensate formed therein and collected on deck or plate 35 is returned through line 36 and Valve 3l and pumped by means of pump 38 through line 39 and valve 4D through vapor phase heating element 4I located in any suitable furnace setting 42. The highly heated vapors from this vapor phase heating Zone are discharged through line 43 controlled by valve 44 into the flashing and Vaporizing zone I'I.

It is quite apparent that the relative proportions of reflux condensate and the temperature to which same is heated permit complete vaporization in flashing or vaporizing zone Il even to the extent of reducing the unvaporized residue therein to coke, and this is one of the features of my invention.

It is also apparent that the reflux condensate collecting on deck or plate 23 is heavier and higher boiling in characteristics than that collected on deck or plate 35 and that the conditions for reconversion in heating elements 29 and 4I are regulated accordingly.

The vapors containing the low boiling product of the process leaving fractionating column 22 pass through vapor line 45 controlled by valve 46 and through line 4l into cooler and condenser 48, the distillate together with the gases passing through line 49 controlled by valve 59 into receiver 5I. The distillate in receiver 5I may be removed through line 52 controlled by valve 53. The gases in receiver 5I may be discharged through line 54 controlled by valve 55. A portion of the distillate may be returned to the fractionating column for cooling purposes to control the character of the distillate through line 56 controlled by valve 5l by means of pump 58 and through line 59.

A portion of the raw oil may be diverted from line 9 through line 63 and may be fed through line 62 and valve 66 into line I5 to mix with and cool the converted material from heating element il. Similarly a portion of the raw oil may be fed into line 133 through line 6l controlled by valve 65 to cool the products from heating element lil. Raw oil from line 63 may also be utilized to cool the heated products from heating element 29 by introducing a portion of the raw oil through line 60 controlled by valve 64 into line 3l.

As examples of the operating conditions and yields of products obtained by the process of my invention a 27 gravity A. P. I. Mid-Continent topped crude was treated, the temperature in heating element El being approximately 900 degrees F. The pressure upon this heating element was approximately 200 pounds per square inch. The heavier reflux condensate from deck or plate 23 was heated in coil 29 to a temperature of approximately 980 degrees F. The lighter reflux from deck or plate 35 was heated in coil fil to a temperature of approximately 1050 degrees F. The pressures upon the heating elements 29 and ll were approximately 150 pounds per square inch. During this operation the residue in flashing or evaporating zone ll was reduced to coke. Approximately 55 per cent of gasoline having an anti-knock value of approximately 60 per cent benzol equivalent was produced, that is, equivalent in anti-knock value to a mixture of Pennsylvania straight run gasoline and benzol, containing 60 per cent of the latter. Approximately 60 pounds of coke per barrel of raw oil charged was made at the same time. The yield of gas was approximately 800 cubic feet per barrel of oil charged. Approximately l0 per cent of pressure distillate bottoms was formed during the operation.

By reducing the temperatures in the vapor phase heating elements, the production of gas was reduced somewhat but the anti-knock value was also lowered. Operating the heating elements "il and 29 at substantially equalized pressure with the flashing Zone l1 at approximately 25 pounds per square inch pressure during this operation, increased the yield of gas somewhat over a similar operation where the same temperature conditions but higher pressure prevailed in the heating elements. Other chargng stock, both .lighter and heavier than that given in the above example, gave parallel results, the lighter charging stock producing larger yields of gasoline and less coke, the heavier vice versa.

Generally speaking, the temperatures which I may employ in heating element Il will vary between 800 degrees F. and 950 degrees F.; that is, those temperatures usually employed in liquidvapor phase operation and the temperature in heating elements 29 and 4| will vary between 950 degrees F. and 1250 degrees F., more or less. Higher tempertaures will tend to produce an excessive gas formation, but the process is adapted to gas making and may be so used if desired, although I prefer to adapt it to the production of a high anti-knock gasoline. By introducing a portion of the raw oil charging stock into the transfer or discharge lines from heating elements 2S and 4l I found that I may substantially reduce the formation of gas especially when high temperatures are employed in these heating elements, as in this manner the heated products may be cooled before sufficient reaction time has been allowed for the excessive formation of gas and coke.

I claim as my invention:

l. The method of decomposing hydrocarbon oils to form low boiling products therefrom which comprises maintaining residual oil products in a decomposing zone at a tempertaure to effect decomposition thereof into coke substantially free from liquid products, removing vapors from said decomposing Zone and supplying fresh oil containing residual products into contact with the removed vapors, thereby vaporizing a portion of said fresh oil and heating the unvaporized residual constituents thereof, discharging said unvaporized residual constituents, free from the vaf the fresh oil before it is supplied into contact with the vapors from said decomposing zone, and heating a heavier one of said condensates to cracking temperature and discharging it into the decomposing zone to maintain a decomposing temperature therein and convert the residual products into coke substantially free from liquid products.

2. The method of decomposing hydrocarbon oils to form low boiling products therefrom which comprises maintaining residual oil products in a decomposing zone at a temperature to effect decomposition thereof, removing vapors from said decomposing zone and supplying fresh oil containing residual products into contact with the removed vapors, thereby vaporizing a portion of 3 said fresh oil and heating the unvaporized residual constituents thereof, discharging said unvaporized residual constituents, free from the vaporized portion, into said zone to be decomposed therein, cooling the combined vapors from said Zone and from the fresh oil to condense therefrom a plurality of fractions of different intermediate boiling point ranges, separately collecting the resulting condensates, heating a lighter condensate thus separated to vaporizing and cracking temperature under pressure to effect conversion thereof, commingling vapor products of said cracking with the fresh oil while the latter is substantially below its vaporizing temperature and before it is supplied into contact with the vapors from said decomposing Zone, and heating a heavier one of said condensates to cracking temperature and discharging it into the decomposing zone to maintain a decomposing temperature therein.

3. A hydrocarbon oil conversion process which comprises maintaining residual oil products at decomposition temperature in the lower portion of an enlarged chamber, supplying fresh oil containing residual products to the vapor space of said chamber and into Contact with vapors therein, a portion of the fresh oil being thereby vapor-- ized in said vapor space and the unvaporized portion thereof descending into said lower portion of the chamber, removing vapors from said chamber and fractionating the same to separate a plurality of reflux condensates therefrom, heating a lighter reflux condensate thus separated to vaporizing and cracking temperature under pressure to effect conversion thereof, commingling vapor products of said cracking with the fresh oil while the latter is substantially below its vaporizing temperature and before it is contacted with the first-mentioned vapors in the vapor space of said chamber, and heating a heavier one of said reuX condensates to cracking temperature and discharging it into said chamber below the point of introduction of the fresh oil to maintain a decomposing temperature therein.

4. The process as dened in claim 3 further characterized in that residual products are reduced to coke in said chamber.

5. A hydrocarbon oil conversion process which comprises maintaining residual oil products at decomposition temperature in the lower portion of an enlarged chamber, supplying fresh oil containing residual products to the vapor space of said chamber and into contact with vapors therein, a portion of the fresh oil being thereby vaporized in said vapor space and the unvaporized portion thereof descending into said lower portion of the chamber, removing vapors from said chamber and fractionating the same to separate a plurality of reuX condensates therefrom, heating one of the reflux condensates thus separated to vaporizing and cracking temperature under pressure to effect conversion thereof, commingling Vapor products of said cracking with the fresh oil while the latter is substantially below its Vaporizing temperature and before it is contacted with the first-mentioned vapors in the vapor space of said chamber, and heating another cf said reux condensates to cracking temperature and discharging it into said chamber below the point of introduction of the fresh oil to maintain a decomposing temperature therein.

JEAN DELATTRE SEGUY.

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